This application proposes a new Clinical Trials Network (CTN) node representing North Texas. The North Texas Node (NTN) is comprised of the University of Texas Southwestern Medical Center in Dallas (UT Southwestern) and seven Community Treatment Providers (CTPs) in Dallas, Ft. Worth, Austin, and El Paso. UT Southwestern brings together a faculty with extensive experience in the preclinical and clinical study of substance use disorders, the design, implementation, and analysis of multi-site, efficacy-effectiveness clinical trials in both adolescents and adults the pharmacological treatment of comorbid disorders, and cultural issues in addiction. UT Southwestern faculty will collaborate with CTPs representing over 11,000 annual inpatient and outpatient admissions for a primary substance use disorder, with large populations of Hispanic/Latino, African-American, adolescent, and female patients. The CTPs and associated sites also offer specialized treatment and outreach programs for HIV+ patients. The NTN utilizes an administrative and organizational structure that carefully considers the CTN structure, its policies and procedures, and the initiation of centralized clinical, data management/statistical, and logistical centers. The Node's organization also provides a strong voice to our CTPs, assuring their presence on all committees, teams, and workgroups. For example, the NTN has initiated mechanisms to develop new protocols that involve a joint CTP-UT Southwestern effort, as evidenced by our Concept Proposal that addresses an unmet clinical need identified by the Node's CTPs. This collaborative structure will enable the NTN to take the lead in the development of future of protocols within the CTN, in addition to ancillary and externally funded studies that maximize the CTN platform. This system also incorporates UT Southwestern's preclinical T32 and clinical R25 NIDA training grants to encourage resident, fellow, and faculty career development within the CTN, including K awards. Protocol implementation will be assured by our exceptionally skilled management team and trainers from UT Southwestern's previous and ongoing multi-site clinical trials and a cadre of CTP sites with significant collaborative research experience. The effectiveness of the NTN in developing, implementing and disseminating the results of clinical trials will be assisted by the NTN's own Performance Assessment System, which will complement the CTN's performance monitors. Our Concept Proposal, which proposes a study of the effects of medication algorithms to treat adolescents with substance use and comorbid disorders, reveals our Node's ability to design state-of-the-art effectiveness trials that maximize the potential of the CTN framework. We believe the structure and organization of the NTN, as well as its committed and highly experienced investigators, complements and extends the work of the CTN.